28317881321 has 2 divisors, whose sum is σ = 28317881322. Its totient is φ = 28317881320.

The previous prime is 28317881233. The next prime is 28317881351. The reversal of 28317881321 is 12318871382.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15840991321 + 12476890000 = 125861^2 + 111700^2 .

It is a cyclic number.

It is not a de Polignac number, because 28317881321 - 2²⁶ = 28250772457 is a prime.

It is not a weakly prime, because it can be changed into another prime (28317881351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14158940660 + 14158940661.

It is an arithmetic number, because the mean of its divisors is an integer number (14158940661).

Almost surely, 2^28317881321 is an apocalyptic number.

It is an amenable number.

28317881321 is a deficient number, since it is larger than the sum of its proper divisors (1).

28317881321 is an equidigital number, since it uses as much as digits as its factorization.

28317881321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129024, while the sum is 44.

The spelling of 28317881321 in words is "twenty-eight billion, three hundred seventeen million, eight hundred eighty-one thousand, three hundred twenty-one".